12 Bizarre Examples of Genetic Engineering

Here’s a look at some genetically engineered plants and animals.

genetically modified miscanthus, an ornamental white feathery grass

M. Rehemtulla / Wikimedia Commons / CC by 2.0

Glow-in-the-dark animals? It may sound like science fiction, but they've been around for years. Cabbages that produce scorpion poison? It's been done. Oh, and the next time you need a vaccine, the doctor might just give you a banana.

These and many other genetically modified organisms exist today because their DNA has been altered and combined with other DNA to create an entirely new set of genes. Genetic engineering (also known as genetic modification) involves using laboratory-based technologies to alter the DNA sequence of an organism. This could mean changing a single base pair (which form the "rungs" of the DNA ladder), deleting a region of DNA, or adding a new segment of DNA. This may be done to transfer a desirable trait from one organism to another. As the National Human Genome Research Institute explains on its website, "Used in research and industry, genetic engineering has been applied to the production of cancer therapies, brewing yeasts, genetically modified plants and livestock, and more."

There are different forms of genetic modification. For centuries, farmers have relied on traditional crop modification, by selectively breeding and cross-breeding plant and animal species based on the traits they wanted to see continue. Lab-based genetic engineering developed in the 1970s and copies desired traits from one organism in another. Genome editing (or CRISPR) is a newer method that's more precise and targeted at making changes to DNA sequences for altered outcomes; these could be aimed at changing physical traits like eye color or reducing disease risk. From the National Human Genome Research Institute: "These technologies act like scissors, cutting the DNA at a specific spot. Then scientists can remove, add, or replace the DNA where it was cut."

You may not realize it, but many of these genetically modified organisms are already a part of your daily life—and your daily diet. In 2020, 92% of U.S. corn, 94% of soybeans, and 96% of cotton were genetically engineered. Many of these plants are used to make ingredients used in other products, which is why it's estimated that 60% to 70% of processed foods on grocery store shelves contain genetically engineered ingredients.

Here’s a look at the some of the weirdest genetically engineered plants and animals already in existence—and many that are coming your way soon. Fortunately there are no humans in this list!

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Glow-in-the-Dark Animals

scientist touches nose of pig bred to glow in the dark

SAM YEH / Getty Images

In 2007, South Korean scientists altered a cat's DNA to make it glow in the dark and then took that DNA and cloned other cats from it, creating a set of fluffy, fluorescent felines. Here’s how they did it: The researchers took skin cells from Turkish Angora female cats and used a virus to insert genetic instructions for making red fluorescent protein. Then they put the gene-altered nuclei into the eggs for cloning, and the cloned embryos were implanted back into the donor cats—making the cats the surrogate mothers for their own clones.

Earlier research in Taiwan created three pigs that glowed fluorescent green. That's Wu Shinn-chih, assistant professor for the Institute and Department of Animal Science and Technology of National Taiwan University (NTU), with one of the pigs in the photo.

What's the point of creating a pet that doubles as a nightlight? Scientists say the ability to engineer animals with fluorescent proteins will enable them to artificially create animals with human genetic diseases.

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medium sized pink pig lays down in large pile of hay

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The Enviropig, or "Frankenswine," as critics call it, is a pig that's been genetically altered to better digest and process phosphorus. Pig manure is high in phytate, a form of phosphorus, so when farmers use the manure as fertilizer, the chemical enters the watershed and causes algae blooms that deplete oxygen in the water and kill marine life.

So scientists added an E. coli bacteria and mouse DNA to a pig embryo. This modification decreases a pig's phosphorous output by as much as 70%, making the pig more environmentally friendly.

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Pollution-Fighting Plants

rows and rows of yellow poplar trees with skinny white trunks

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Scientists at the University of Washington are engineering poplar trees that can clean up contamination sites by absorbing groundwater pollutants through their roots. The plants then break the pollutants down into harmless byproducts that are incorporated into their roots, stems and leaves or released into the air.

In laboratory tests, the transgenic plants are able to remove as much as 91% of trichloroethylene—the most common groundwater contaminant at U.S. Superfund sites—out of a liquid solution. Regular poplar plants removed just 3% of the contaminant.

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Venomous Cabbage

whole head of green cabbage covered in holes eaten by caterpillars

Chonticha Vatpongpee / Getty Images

Scientists have taken the gene that programs poison in scorpion tails and looked for ways to combine it with cabbage. Why would they want to create venomous cabbage? To limit pesticide use while still preventing caterpillars from damaging cabbage crops. These genetically modified cabbages would produce scorpion poison that kills caterpillars when they bite leaves—but the toxin is modified so it isn’t harmful to humans.

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Web-Spinning Goats

white small goat with tiny horns stands outside farm with grass

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Strong, flexible spider silk is one of the most valuable materials in nature, and it could be used to make an array of products—from artificial ligaments to parachute cords—if we could just produce it on a commercial scale. In 2000, Nexia Biotechnologies announced it had the answer: a goat that produced spiders' web protein in its milk.

Researchers inserted a spiders’ dragline silk gene into the goats’ DNA in such a way that the goats would make the silk protein only in their milk. This "silk milk" could then be used to manufacture a web-like material called Biosteel.

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Fast-Growing Salmon

atlantic salmon swimming in river surrounded by tiny particles

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AquaBounty's genetically modified salmon grows twice as fast as the conventional variety. The company says the fish has the same flavor, texture, color and odor as a regular salmon, and can help address overfishing problems. However, the debate continues over whether the fish is safe to eat or good for the environment.

Genetically engineered Atlantic salmon has an added growth hormone from a Chinook salmon that allows the fish to produce growth hormone year-round. Scientists were able to keep the hormone active by using a gene from an eel-like fish called an ocean pout, which acts as an "on switch" for the hormone.

Some opponents are concerned that if this fish were ever to escape or be introduced into ecosystems, it might be about outcompete native species and become invasive.

The FDA approved the sale of the salmon in the U.S. in 2015, marking the first time a genetically modified animal was approved for sale in the U.S.

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'Flavr Savr' Tomato

young male scientist inspects gmo tomatoes in greenhouse lab

Longhua Liao / Treehugger

The Flavr Savr tomato was the first commercially grown genetically engineered food to be granted a license for human consumption. By adding an antisense gene, the California-based company Calgene hoped to slow the ripening process of the tomato to prevent softening and rotting, while allowing the tomato to retain its natural flavor and color.

The FDA approved the Flavr Savr in 1994; however, the tomatoes were so delicate that they were difficult to transport, and they were off the market by 1997. On top of production and shipping problems, the tomatoes were also reported to have a very bland taste: "The Flavr Savr tomatoes didn’t taste that good because of the variety from which they were developed. There was very little flavor to save," said Christ Watkins, a horticulture professor at Cornell University.

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Banana Vaccines

a large bunch of green bananas ripening on tree in jungle

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People may soon be getting vaccinated for diseases like hepatitis B and cholera by simply taking a bite of banana. Researchers have successfully engineered bananas, potatoes, lettuce, carrots and tobacco to produce vaccines, but they say bananas are the ideal production and delivery vehicle.

When an altered form of a virus is injected into a banana sapling, the virus' genetic material quickly becomes a permanent part of the plant's cells. As the plant grows, its cells produce the virus proteins—but not the infectious part of the virus. When people eat a bite of a genetically engineered banana, which is full of virus proteins, their immune systems build up antibodies to fight the disease—just like a traditional vaccine.

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Less Flatulent Cows

brown cow with nose covered in wet grass eats on field with friends

Andre Wilms / Getty Images

Cows produce significant amounts of methane as a result of their digestion process; it’s produced by a bacterium that’s a byproduct of cows’ high-cellulosic diets that include grass and hay. Methane is a major contributor—second only to carbon dioxide—to the greenhouse effect, so scientists have been working to genetically engineer a cow that produces less methane.

Agriculture research scientists at the University of Alberta have identified the bacterium responsible for producing methane and designed a line of cattle that creates 25% less methane than the average cow.

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Genetically Modified Trees

group of yellow loblolly pines circled around natural lake

Douglas Sacha / Getty Images

Trees are being genetically altered to grow faster, yield better wood and even detect biological attacks. Proponents of genetically engineered trees say biotechnology can help reverse deforestation while satisfying demand for wood and paper products. For example, Australian eucalyptus trees have been altered to withstand freezing temperatures, and loblolly pines have been created with less lignin, the substance that gives trees their rigidity.

However, critics argue that not enough is known about designer trees’ effect on their natural surroundings—they could spread their genes to natural trees or increase wildfire risk, among other drawbacks. Still, the USDA gave approval in May 2010 for ArborGen, a biotechnology company, to begin field trials for 260,000 trees in seven southern states.

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Medicinal Eggs

close up of white chicken eggs in carton

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British scientists have created a breed of genetically modified hens that produce cancer-fighting medicines in their eggs. The animals have had human genes added to their DNA so that human proteins are secreted into the whites of their eggs, along with complex medicinal proteins similar to drugs used to treat skin cancer and other diseases.

What exactly do these disease-fighting eggs contain? The hens lay eggs that have miR24, a molecule with potential for treating malignant melanoma and arthritis, and human interferon b-1a, an antiviral drug that resembles modern treatments for multiple sclerosis.

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Super Carbon-Capturing Plants

green Switchgrass ( panicum virgatum ) with sunny haze

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Humans add about nine gigatons of carbon to the atmosphere annually, and plants and trees absorb about five of those gigatons. The remaining carbon contributes to the greenhouse effect and global warming, but scientists are working to create genetically engineered plants and trees that are optimized for capturing this excess carbon.

Carbon can spend decades housed in the leaves, branches, seeds and flowers of plants; however, carbon allocated to a plant’s roots can spend centuries there. Therefore, researchers hope to create bioenergy crops with large root systems that can capture and store carbon underground. Scientists are currently working to genetically modify perennials like switchgrass and miscanthus because of their extensive root systems.